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A342394
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a(n) = Sum_{k=1..n} k^(gcd(k,n) - 1).
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3
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1, 3, 11, 68, 629, 7793, 117655, 2097228, 43046772, 1000000649, 25937424611, 743008379146, 23298085122493, 793714773371841, 29192926025401528, 1152921504608945960, 48661191875666868497, 2185911559738739835591, 104127350297911241532859
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OFFSET
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1,2
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LINKS
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FORMULA
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MATHEMATICA
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a[n_] := Sum[k^(GCD[k, n] - 1), {k, 1, n}]; Array[a, 19] (* Amiram Eldar, Mar 10 2021 *)
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PROG
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(PARI) a(n) = sum(k=1, n, k^(gcd(k, n)-1));
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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